R1:32e4a7a37f1f

Use transactions to show edit history for Configuration

Summary: Use ApplicationTransactions in Config to create an edit history. Resolves T2256.

Test Plan: {F28477}

Reviewers: btrahan, codeblock

Reviewed By: codeblock

CC: aran

Maniphest Tasks: T2256

Differential Revision: https://secure.phabricator.com/D4314